| Observation data EpochJ2000 EquinoxJ2000 | |
|---|---|
| Constellation | Delphinus |
| Right ascension | 20h 30m 42.330s[1] |
| Declination | +07° 49′ 35.78″[1] |
| Characteristics | |
| Spectral type | T1.5[2][3] |
| Apparent magnitude (i(SDSS)) | 21.810 ± 0.140[3] |
| Apparent magnitude (z(SDSS)) | 17.195 ± 0.014[3] |
| Apparent magnitude (J(2MASS)) | 14.227 ± 0.029[3] |
| Apparent magnitude (H(2MASS)) | 13.435 ± 0.033[3] |
| Apparent magnitude (Ks(2MASS)) | 13.319 ± 0.039[3] |
| Apparent magnitude (w1(WISE)) | 12.956 ± 0.025[3] |
| Apparent magnitude (w2(WISE)) | 12.122 ± 0.025[3] |
| Apparent magnitude (w3(WISE)) | 10.964 ± 0.110[3] |
| Astrometry | |
| Proper motion (μ) | RA: 664.047mas/yr[1] Dec.: -111.659mas/yr[1] |
| Parallax (π) | 102.7966±0.8009 mas[1] |
| Distance | 31.7 ± 0.2 ly (9.73 ± 0.08 pc) |
| Other designations | |
| WISE J203042.79+074934.7[2][3] WISE J2030+0749[2][3] | |
| Database references | |
| SIMBAD | data |
WISE J2030+0749 is a nearbybrown dwarf ofspectral type T1.5,[2][3] in the constellationDelphinus, approximately 31.7light-years (9.7parsecs) from Earth.[1]
The discovery of WISE J2030+0749 was announced in 2013 by Maceet al.[2] and independently by Bihainet al.[3]
Maceet al. selected T-type brown dwarf candidates from theWISE All-Sky source catalogue and carried out follow up observations using a variety of telescopes. On September 11, 2011 WISE J2030+0749 was observed using SpeX at theInfrared Telescope Facility (IRTF). The discovery paper was submitted toThe Astrophysical Journal Supplement, accepted for publication on 2013 January 15 and published in March, 2013. The total number of brown dwarfs announced in Maceet al. (2013) is 87, all are of T-type.[2]
Bihainet al. selected sources with colours typical for T dwarfs from theWISE All-Sky source catalogue and checked them for highproper motion using older surveys:2MASS,DENIS,SDSS,SSS,DSS andUKIDSS. Three objects among about ten candidates, including WISE J2030+0749, were selected for spectroscopic follow up with theLarge Binocular Telescope (LBT). On November 8, 2012 Bihainet al. carried out follow up observations of WISE J2030+0749 with near-Infrared spectrograph LUCI 1 on LBT. On June 25, 2013Astronomy & Astrophysics received the discovery paper, which was accepted for publication 10 July 2013.[3]
The distance of WISE J2030+0749 was estimated by Bihainet al. using meanabsolute magnitudes of single T1/T2 dwarfs, derived by Dupuy & Liu (2012) from trigonometric parallaxes:[4] 10.5 ± 2.6pc (34.2 ± 8.5ly).[3]
Itsparallax was later measured by theGaia space telescope, with theGaia DR3 parallax corresponding to a distance of9.73±0.08 pc (31.7±0.2 ly).[1]
Two other T dwarfs, announced in Bihainet al (2013):
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